In vitro anticancer screening of South African plants

Abstract

A total of 7500 plant extracts were screened for in vitro anticancer activity against a panel of three human cell lines (breast MCF7, renal TK10 and melanoma UACC62). Extracts were classified into four categories based on their total growth inhibition of the cell lines. A hit rate of 5.9% was obtained for extracts which showed moderate activity and these were screened by the NCI against a panel of sixty human cancer cell lines. The extracts of plant species with limited published information for their anticancer properties were subjected to bioassay-guided fractionation and the active constituents isolated and identified. The largest number of plant specimens in this study was from the family Asteraceae, which is rich in sesquiterpene lactones. Although the extracts of the plants were randomly selected, 68% of these plant species were reported to be used medicinally. Based on our data, it appears that unrelated medicinal use of the source plants may serve as an initial guide to collections for anticancer screening